Kim Fennebresque, chairman and chief executive of Cowen Group, told analysts: “There are new business initiatives that were discussed on the roadshow that we were looking into over the coming six to 18 months but there has been no development.”

The bank declined to comment further.

Cowen’s initial public offering prospectus said that by becoming a public company it could grow by adding products, hiring staff and by adding sectors that fit its business lines. The bank specialises in the healthcare, technology, media and telecommunications and consumer sectors.

Cowen floated in the US last month but did not receive any of the proceeds from the $180m listing, which went to its former parent.

In its first results since starting public life, the bank swung into profit in the last quarter after a one time-gain in the conversion of its New York Stock Exchange membership. In the first half, investment banking revenue rose by two-thirds and equity underwriting fees doubled over the same period last year.

Fennebresque said at the time of the results: “We are excited about strategic personnel investments we made during the first half of the year as we began to build our business in anticipation of becoming an independent public company, including the addition of a seasoned options team, a number of middle market sales professionals and four senior research analysts."

Since the group floated, rival boutique Evercore Partners has listed and its shares have risen by a third over their issue price. Last week Keefe, Bruyette & Woods, another financial services boutique, also filed for a $100m initial public offering.